Needle cooling device for sewing machines



May 11, 1937- H. J. LE vEscoN-E 2,080,322

NEEDLE COOLING DEVICE FOR SEWING MACHINES Filed April 5, 1953 7 Y g5 g A15/622, gg gg m 94,2

. l HJ LcVsco/zc which is adapted to Patented May 1,1, 193':

UNITD STATES PATENT OFFICE NEEDLE oooLmdonlacEron SEWING i i chinas, and more particularly to improved means EINES narnia J. Le vescontawemm springs, nl., s-

signor to Union SpecialMachine Company, Chicago, Ill., a corporation of Illinois Application April 5, 1933,' Serial No. 664,636

3 Claims. (Cl- 112-218) The present invention relates. to sewing mafor cooling the sewing machine needles in order to prevent the same from becoming overheated. An object of the invention is to provide, ina sewing machine, an impiroved needle cooling mechanism of simplified construction wherein an air pumping mechanismV is adapted to be operated by the reciprocation ofthe needle bar to direct a blast of air against the sewing needles. A further object of the invention is to provide an improved needle coolingmechanism of simpliiled construction wherein an air pumping mechanism is adapted to be operated by the reciprocation of the needle bar to direct a blast of air across the path of the sewing needles.

A further object of the invention is to provide an` improved pumping mechanism which is adapted to force a blast of air across the needle of a sewing machine wherein the needle bar serves as the piston rod.

A still further object of the invention is to provide an improved air pump for cooling the needies of a sewing machine wherein the pump cylinder is formed as an integral part of and an extension of a needle bar bushing whereby to properly x the pump cylinder in alignment with the needle bar. V A still further object of the invention is to provide, in a sewing machine, an improved air pumping unit wherein the pump cylinder is formed as an integral part of the needle bar bushing and wherein the needle bar carries a piston head cylinder.

reciprocate within the pump The invention still further aims to provide an improved needle cooling unit, of the type referred to, which may be readily applied to any sewing machine. but which is particularly useful in high speed machines and those which are adapted to operate upon heavy fabrics, paper, or the like, wherein there is'a pronounced tendency of the needle to become overheated. I

The invention further provides a needle .cooling unit, of the type referred to, which is oi simple construction, which is inexpensively manufactured and easily installed, and which will effectually cool the needles in order to preserve thread.

described.

Figure 1 is an elevation showing the coolingmechanism as applied to a sewing machine.

rliig. 2 is a sectional view, in detail, showing the cylinder head and control valves.

Fig. 3 is a top plan view showing the nozzle in positionV to direct a blast of air against the needles.

Fig. 4 is a top plan view, partly in section, showing the manner of securing the pumping unit to the needle head.

Here'tofore, considerable diiiiculty has been encountered in the operation of high speed sewing machines and machines used for sewing heavy fabrics, paper, orV the like, in that the sewing needles'tend to become overheated which'results in causing them to lose their temper. This heating of the needles is caused by the frictional resistance oiered `by the fabric to the passage of the needles therethrough and often results in the burning off of the thread. When the needles become overheated, they become roughened and the points become dulled so that the frictional resistance increases. It is apparent therefore that by keeping the needles cool,l the points will be preserved and the surfaces will retain their smoothness which facts will keep the resistance which may be quickly installed in a sewing machine without the necessity of any machining of the parts. The cooling unit comprises a pump mechanism wherein the needle bar carries a plunger and is adapted to act as the piston and reciprocate within the pump cylinder whereby to force a blastof air through a connectiong tube against the needles when they are above the' work. In this manner, the needles are suillciently cooled to permit the machine to operate continuously. The pumping unit is particularly advantageous in that it may be readily applied to a machine already on the `market and also in the fact that the pump cylinder may be made of varying capacities without changing the manner of mounting the unit on the sewing machine.

Referring more in detail to the accompanying drawing, the overhanging arm I0 of a sewing machine is in the form of a hollow housing which therein suitable sleeve bushings I1, I8 within,

which the needle bar reciprocates. The needle bar I2 carries a clamping member I9 which is adapted to receive the sewing machine needles 23 which in the illustrated embodiment of the invention are arranged in a line oblique to the line of feed and which pass through suitable openings 2l in the presser foot 22 which, in turn, is secured to the presser bar 23. The feed dog 24 operates between the slots in the throat plate 25 to feed the fabric 26 to and away from the sewing mechanism.

The upper lug or bearing block I5 is provided with a vertical opening from which extends a vertical slot'29 (Fig. 4). An opening 30 in the lug I5 intersects the slot at right angles to the plane thereof and is adapted to receive a bolt 3|.

. A similar arrangement is provided in the lower lug I6 and the sleeve bushing I8 is inserted in the vertical opening and isfirmly clamped therein by tightening the bolt 3I. The upper bushing I1.is similarly inserted in the vertical opening in the lug I 5 and is clamped therein by the bolt 3 I. This bushing I1 is provided with an integral cylinder portion 32 whichextends above the lug I5 andthe lower end o! the cylinder rests upon said lugs. The needle bar I2 passes through the bushing I1 and extends into the cylinder 32. f A piston head 33 is secured by a screw 34 to the upper end of the needle bar and is adapted to form, together with the needle bar, a. piston which reciprocates within the cylinder 32. The upper end of the cylinder 32 is externally threaded to receive the threaded end of the cylinder head 35. The cylinder head 35 is provided with achamber 36 which communicates with a port 31 which is open to the atmosphere and a port 38 which communicates withthe interior of the cylinder 33. The 4opposite end of the chamber 36 is internally threaded to receive the threaded end of an angle pipe 39. The angle pipe is provided with a recessed portion 40 which is internally threaded to receive a sleeve 4I at the end thereof. A ball check valve 42 is adapted to normally close the port 31 by the action of a coil spring 43 one end of which rests uponthe sleeve 4I. through the sleeve 4I is normally closed by a ball check valve 44 which is held by a spring 45, one end of which rests upon the ledge 46 oi' the recessed portion 40. The cylinder 32 is'provided with an opening 41 at the lower end thereof. 'I'his opening serves as an air vent and also affords easy access to the interior of the cylinder whereby the bushing and piston may be oiled. Secured to the' angle pipe 39 is a downwardly extending tube 48 which is provided with a nozzle 49 which is expanded in order to direct a blast of air laterally against the needles 20. The tube may be supported by a bracket 50 secured to the sewing head. It will be particularly noted that theopen end of the nozzle 49 is disposed in a. plane which is parallel to the longitudinal axes of the needles 20, or as illustrated in theipresent embodiment of the invention, the open end of the nozzle is disposed at a vertical plane, so that the blast of air issuing therefrom will be directed across the needles ,so as to afford, in this manner, a maxi-` mum cooling eiIect. v

In the operation of the device, the dewnward They opening movement of the needle bar I2 and the piston 3| will create a vacuum in the chamber 36 in the cylinder head. The pressure in the chamber 3 6 will thereby be less than atmospheric pressure whereby the check valve 44 will be closed and check valve 42 will be opened to permit air to enter the cylinder 32 through the port 38. Upon the return or upward movement of the needle bar I2, the piston 33 will force the air into the chamber 36, thus closing the valve 42 and opening the valve 44 whereby the air is urged through the angle pipe 39 and tube 48 and directed by the nozzle 49 against the needles when the needle bar is on the upward stroke and the said needles are receding from the work. This operation is repeated so that upon each upward stroke of the needle bar, a blast of air is directed against the needles in order to cool the same. From the foregoing description, it willbe noted that the blast of air is onlydirected against the needles at a time when it is possible to obtain a cooling eiiect, that is, when the needles are out of the work and that the volume of air discharged against the needles per unit of time'is directly proportionate to the speed of the sewing machine and similarly the velocity of the air issuing from the nozzle is directlyvproportionate to the speed of the sewing machine so that the cooling eiIect on the needles is increased as the speed of the machine is lncreased. It will be understood thatthe nozzle 49 may be arranged in various positions depending upon the` arrangement of the needles in order to insure a proper cooling eect by directing the blast of air laterally against the needles.

To install the pumping unit on a sewing machine,- it is only' necessary to loosen the bolt 3I and remove the usual bushing and then insert the sleeve portion I1 of the cylinder 32 in place thereofA and tighten the bolt 3l. After the piston head 33 is secured to the needle bar, the cylinder L -head 35, with the control valves and angle pipe 39 attached thereto, may be screwed to the cylinder 32. The tube 48'is then properly fastened to the downwardly extending part of the angle pipe 33 and positioned so that the nozzle 43 will direct the air, which is forced therethrough, against the needles to cool the same. yThe bracket 'member 50 is adapted to additionallysupport the tube in proper position.

It is, of course, to be understood that minor changes in details of construction and arrangement of parts may be made without departing from the scope of the appended claims.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:i

1. In a sewing machine, a needle head, a-needle bar reciprocating thereima needle carried by said needle bar, and means for directing a blast of airk across the needle for cooling the same. said means including a pump cylinder, a piston therein connected to said needle bar in axial alignment therewith, a cylinder head carrying control valves and apipe connected to said cylinder head and terminating in a nozzle adjacent said needle. said' control valves adapted to permit a blastoi air to be discharged from said nozzle laterally against the needle on lthe upstroke of .the needle bar.

2. In a sewing machine. a needle head, a needle e bar reciprocating therein, a needle carried by said jacent the needle, a pump cylinder formed as an u integral part of the needle bar bushing and located in axial alignment therewith. a piston therein connected to said needle bar in axial alignment therewith, and a cylinder ,head carrying control valves and connected to said tubular member, said valves adapted to permit the discharge of air from said nozzle across the needle on the upstroke of said needle bar.

3. In a sewing machine, a needle head, a needle l0 bar reciprocating therein, a needle carried by said needle bar, a cylinder mounted on saidneedle head and having'an inwardly offset depending sleeve portion extending into the needle head and serving as a bushing for said needle bar. a piston head carried by said needle bar and operating within said cylindenvnlve.l means for permitting the discharge o! air from said cylinder on the upstroke oi' the needle bar,V and conduit means i'or directing the blast of air laterally against said needle for cooling the same as it recedes from the work.

HAROID J. LE VESCONTE. 

